125's were legal for the road race.
Bart won the men's 30k road race with a big lead on 125's. Strangely, Felix ended up way back in 8th place on 125's. I think everyone else in the top 10 was on 110's.
Sadrine Tas dominated the road race (and almost every women's race) on 3x110+100. Bianca Roosenboom got 2nd place on the road with 125's, but nearly all of the other top women were on 3x110+100 or 4x110. I think even Erin Jackson was on 3x110+100.

Until 125's are allowed in all events and the top skaters train on them all the time, I don't think we will have a clear picture of their capabilities. 125's seem to favor skaters with longer strides and more glide which is the same thing that happened with 110's back in the 2008-2009. In the midwest, the most successful marathon skater so far this year has been an ice skater skating with ice technique on borrowed 125's.

Until 125's are allowed in all events and the top skaters train on them all the time, I don't think we will have a clear picture of their capabilities.

I agree. That is definitely true. A few more generations of wheel/hub development will also help.

On the other hand, Felix has many years of experience on 125's, and quite a few lesser known skaters beat him in the road race on 110's (of course anyone can have a bad day). People have been frequently claiming that with current technology and current regulations, it's difficult or impossible to keep up on 110's, and I keep hearing that the guys/gals on 125's are just "walking away" from the others on 110's. I'm just a little bit skeptical about some of these claims.

On a completely different note...
It's great to see a few race reports, photos and videos in the "speed events" section. I miss the old days of racereports.net.